ON THE INTERPRETATION OF UNUSUAL EVENTS 
IN GEOLOGIC RECORDS ILLUSTRATED 
BY RECENT EXAMPLES. 
FREDERIC W. SIMONDS. 
AN examination of many geologic reports will not fail to 
show that the working geologist, as a rule, devotes but little 
time to the interpretation of events, though the most valuable 
data may be furnished by the very rocks which, as a stratigrapher, 
he indicates on his map or describes in his notebook. To 
search out relations of rocks stratigraphically is, of course, one 
thing ; to picture in the mind the conditions that prevailed at 
the time of their deposition is another and a different thing. 
But while none will dispute the value of stratigraphic work, 
the value of interpretation should not be underestimated, for 
by it we gain our clearest insight into the physical conditions 
of the past. That it is to a great extent theoretical may 
be admitted, yet the results of indirect evidence may approxi- 
mate the truth. In this paper it is my purpose to show that 
under some conditions, especially when unusual events have 
: been recorded, there is not only difficulty in making the 
proper interpretation, but even danger that the interpretation 
may become misleading — a partial truth being, under some 
circumstances, conducive to positive error. 
Throughout the various ages of the earth, as n ond by 
sedimentary deposits, faunas have succeeded faunas, and floras 
have succeeded floras. At times the exuberance of life must 
have been great, so numerous are the imbedded remains; but 
whether numerous or scarce, they are especially useful to the 
working geologist in that they enable him to recognize strata. 
As fossils they are figured and described by the paleontologist, 
who views them mainly from a biologic standpoint. They also 
! Read before Section E, Geology and Geography, American Association for 
the Advancement of Science, August 23, 1899. 
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